Digestive a-amylases from Tecia solanivora larvae (Lepidoptera:Gelechiidae): response to pH, temperature and plant amylase inhibitors

• Autor(a) principal: Valencia-Jiménez, Arnubio
• Data de Publicação: 2008
• Outros Autores: Arboleda Valencia, Jorge W., Ávila, A. López, Grossi-de-Sá, Maria de Fátima
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UCB
• Texto Completo: http://twingo.ucb.br:8080/jspui/handle/10869/406; https://repositorio.ucb.br:9443/jspui/handle/123456789/7541
• topic: A-Amylase; Tecia solanivora; Amylase inhibitor; Potato

The biochemical properties of the digestive alpha-amylase from Tecia solanivora larvae, an important and invasive insect pest of potato (Solanum tuberosum), were studied. This insect has three major digestive a-amylases with isoelectric points 5.30, 5.70 and 5.98, respectively, which were separated using native and isoelectric focusing gels. The alpha-amylase activity has an optimum pH between 7.0 and 10.0 with a peak at pH 9.0. The enzymes are stable when heated to 50_C and were inhibited by proteinaceous inhibitors from Phaseolus coccineus (70% inhibition) and P. vulgaris cv. Radical (87% inhibition) at pH 6.0. The inhibitors present in an amaranth hybrid inhibited 80% of the activity at pH 9.0. The results show that the alpha-amylase inhibitor from amaranth seeds may be a better candidate to make genetically-modified potatoes resistant to this insect than inhibitors from common bean seeds.